Let's Program the Transistors
In an earlier post, NAND and NOR gate using CMOS Technology, we have seen the implementation of 2 input NAND and NOR gate using CMOS technology. In this article, we will discuss how to implement 2 input AND and OR gate using CMOS technology. Generally in our academic curriculum, students are taught AND and OR…
A test chip is a small-scale integrated circuit that is specifically designed for testing purposes, feasibility checks and performance analysis. It serves as a platform for evaluating the functionality of individual circuit blocks, testing the reliability of manufacturing processes, and verifying the performance of the design before it is implemented in a larger chip. Test…
MPW stands for Multi-Project Wafer, which is a cost-effective way to prototype integrated circuits. In an MPW, multiple projects share a single wafer during the fabrication process, which enables lower costs by spreading the cost of the wafer among multiple projects. Typically, several customers with small designs collaborate to share the costs of the wafer…
A wafer is a thin slice of semiconductor material, typically made of silicon, that serves as the substrate for the fabrication of integrated circuits in the field of VLSI. During the fabrication process, the wafer undergoes a series of processes such as doping, lithography, etching, and deposition to create the desired patterns and structures for…
Resistive divider circuit can alternatively be called as voltage divider circuit. Such a circuit is shown in the following figure: This circuit divides the input voltage Vin depending on the resistance values according to the following formula: Vout = Vin x (R2/(R1 + R2)) Vout is the output voltage, which is nothing but the voltage…
Now we are ready to simulate the layout view off this cell. Let’s open up the schematic view of the cell and copy the SPICE code. Go back to the layout view and paste the SPICE code. Increase the text size of the spice code to 10 by going to its object property (Ctrl+I). The…
Open the layout view of the Resistive_divider cell and then copy/paste (Ctrl+C/Ctrl+V) an additional resistor. Running a DRC (pressing F5) on the above layout results in the following error. By pressing > we see that there is too little space between the N-wells. Move the Nodes apart until the layout passes the DRCs. Of-course the…
Now we would simulate the resistive divider circuit which has been built, and would observe the output voltage w.r.t. a particular input voltage. For this we need to write a SPICE code which would give the description of the input voltage and would indicate the type of simulation we want to perform. Writing SPICE Code…
Before starting the schematic design let’s celebrate the fact that the most commonly used following shortcuts in our daily life are also valid for Electric VLSI. Now we would build a resistive divider circuit. Go to the schematic view of the Resistive_divider cell. Select the N-Well resistor Node and then copy the same by pressing Ctrl+C….
LTspice is a free software which performs SPICE simulations for electronic circuits. We use LTspice for spice simulation of the circuit designed in Electric. Setting in Electric Following are the steps to be followed to set up LTspice with Electric: Ensure LTspice is installed on your computer. Go to File –> Preferences –> Categories –>…